From: Lizhi Hou Date: Wed, 28 Jan 2026 00:23:56 +0000 (-0800) Subject: accel/amdxdna: Hold mm structure across iommu_sva_unbind_device() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9162439ad792afcddc04718408ec1380b7a5f63;p=thirdparty%2Fkernel%2Flinux.git accel/amdxdna: Hold mm structure across iommu_sva_unbind_device() Some tests trigger a crash in iommu_sva_unbind_device() due to accessing iommu_mm after the associated mm structure has been freed. Fix this by taking an explicit reference to the mm structure after successfully binding the device, and releasing it only after the device is unbound. This ensures the mm remains valid for the entire SVA bind/unbind lifetime. Fixes: be462c97b7df ("accel/amdxdna: Add hardware context") Reviewed-by: Mario Limonciello (AMD) Signed-off-by: Lizhi Hou Link: https://patch.msgid.link/20260128002356.1858122-1-lizhi.hou@amd.com --- diff --git a/drivers/accel/amdxdna/amdxdna_pci_drv.c b/drivers/accel/amdxdna/amdxdna_pci_drv.c index 45f5c12fc67fb..fdefd9ec20668 100644 --- a/drivers/accel/amdxdna/amdxdna_pci_drv.c +++ b/drivers/accel/amdxdna/amdxdna_pci_drv.c @@ -82,6 +82,8 @@ static int amdxdna_drm_open(struct drm_device *ddev, struct drm_file *filp) ret = -ENODEV; goto unbind_sva; } + client->mm = current->mm; + mmgrab(client->mm); init_srcu_struct(&client->hwctx_srcu); xa_init_flags(&client->hwctx_xa, XA_FLAGS_ALLOC); mutex_init(&client->mm_lock); @@ -116,6 +118,7 @@ static void amdxdna_client_cleanup(struct amdxdna_client *client) drm_gem_object_put(to_gobj(client->dev_heap)); iommu_sva_unbind_device(client->sva); + mmdrop(client->mm); kfree(client); } diff --git a/drivers/accel/amdxdna/amdxdna_pci_drv.h b/drivers/accel/amdxdna/amdxdna_pci_drv.h index 6580cb5ec7e2f..f08406b8fdf93 100644 --- a/drivers/accel/amdxdna/amdxdna_pci_drv.h +++ b/drivers/accel/amdxdna/amdxdna_pci_drv.h @@ -130,6 +130,7 @@ struct amdxdna_client { struct iommu_sva *sva; int pasid; + struct mm_struct *mm; }; #define amdxdna_for_each_hwctx(client, hwctx_id, entry) \